var Base64 = {
    base64EncodeChars : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",
    base64DecodeChars : new Array (
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
            52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
            -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
            15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
            -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
            41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1),
    encode : function (str) {
        var out, i, len;
        var c1, c2, c3;

        len = str.length;
        i = 0;
        out = "";
        while (i < len) {
            c1 = str.charCodeAt (i++) & 0xff;
            if (i == len) {
                out += Base64.base64EncodeChars.charAt (c1 >> 2);
                out += Base64.base64EncodeChars.charAt ((c1 & 0x3) << 4);
                out += "==";
                break;
            }
            c2 = str.charCodeAt (i++);
            if (i == len) {
                out += Base64.base64EncodeChars.charAt (c1 >> 2);
                out += Base64.base64EncodeChars.charAt (((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4));
                out += Base64.base64EncodeChars.charAt ((c2 & 0xF) << 2);
                out += "=";
                break;
            }
            c3 = str.charCodeAt (i++);
            out += Base64.base64EncodeChars.charAt (c1 >> 2);
            out += Base64.base64EncodeChars.charAt (((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4));
            out += Base64.base64EncodeChars.charAt (((c2 & 0xF) << 2) | ((c3 & 0xC0) >> 6));
            out += Base64.base64EncodeChars.charAt (c3 & 0x3F);
        }
        return out;
    },

    decode : function (str) {
        var c1, c2, c3, c4;
        var i, len, out;

        len = str.length;
        i = 0;
        out = "";
        while (i < len) {
            /* c1 */
            do {
                c1 = Base64.base64DecodeChars[str.charCodeAt (i++) & 0xff];
            } while (i < len && c1 == -1);
            if (c1 == -1)
                break;

            /* c2 */
            do {
                c2 = Base64.base64DecodeChars[str.charCodeAt (i++) & 0xff];
            } while (i < len && c2 == -1);
            if (c2 == -1)
                break;

            out += String.fromCharCode ((c1 << 2) | ((c2 & 0x30) >> 4));

            /* c3 */
            do {
                c3 = str.charCodeAt (i++) & 0xff;
                if (c3 == 61)
                    return out;
                c3 = Base64.base64DecodeChars[c3];
            } while (i < len && c3 == -1);
            if (c3 == -1)
                break;

            out += String.fromCharCode (((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));

            /* c4 */
            do {
                c4 = str.charCodeAt (i++) & 0xff;
                if (c4 == 61)
                    return out;
                c4 = Base64.base64DecodeChars[c4];
            } while (i < len && c4 == -1);
            if (c4 == -1)
                break;
            out += String.fromCharCode (((c3 & 0x03) << 6) | c4);
        }
        return out;
    }
};

var Charset = {
    utf16to8 : function (str) {
        var out, i, len, c;

        out = "";
        len = str.length;
        for (i = 0; i < len; i++) {
            c = str.charCodeAt (i);
            if ((c >= 0x0001) && (c <= 0x007F)) {
                out += str.charAt (i);
            } else if (c > 0x07FF) {
                out += String.fromCharCode (0xE0 | ((c >> 12) & 0x0F));
                out += String.fromCharCode (0x80 | ((c >> 6) & 0x3F));
                out += String.fromCharCode (0x80 | ((c >> 0) & 0x3F));
            } else {
                out += String.fromCharCode (0xC0 | ((c >> 6) & 0x1F));
                out += String.fromCharCode (0x80 | ((c >> 0) & 0x3F));
            }
        }
        return out;
    },
    utf8to16 : function (str) {
        var out, i, len, c;
        var char2, char3;

        out = "";
        len = str.length;
        i = 0;
        while (i < len) {
            c = str.charCodeAt (i++);
            switch (c >> 4) {
                case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
                // 0xxxxxxx
                out += str.charAt (i - 1);
                break;
                case 12: case 13:
                // 110x xxxx   10xx xxxx
                char2 = str.charCodeAt (i++);
                out += String.fromCharCode (((c & 0x1F) << 6) | (char2 & 0x3F));
                break;
                case 14:
                    // 1110 xxxx  10xx xxxx  10xx xxxx
                    char2 = str.charCodeAt (i++);
                    char3 = str.charCodeAt (i++);
                    out += String.fromCharCode (((c & 0x0F) << 12) |
                            ((char2 & 0x3F) << 6) |
                            ((char3 & 0x3F) << 0));
                    break;
            }
        }

        return out;
    }
};